Nancy Drew: Mystery of the Ghostwriter's Cruise (1978)

Synopsis
by Sarah Sloboda

Nancy Drew, teenage crime-solver, found mysteries to unravel in all of her adventures on her 1977 Sunday-evening series, which was based on a children's novel series of the same name. In "Mystery of the Ghostwriter's Cruise," while on ship with a famous writer, Nancy has to figure out who's attempting to kill the famous author.